In a multiple-compressor system, such as a refrigeration system, one challenge is to maintain sufficient oil level in each of the compressors whether the compressor is running or not. Designing a system capable of moving equal amounts of oil to different compressors is difficult due to variations in the individual compressors and piping configurations to those compressors. A particular example of the state of the art with respect to suction gas distribution in a parallel compressor assembly is represented by WIPO patent publication WO2008/081093 (Device For Suction Gas Distribution In A Parallel Compressor Assembly, And Parallel Compressor Assembly), which shows a distribution device for suction gas in systems with two or more compressors, the teachings and disclosure of which is incorporated in its entirety herein by reference thereto. A particular example of oil management in systems having multiple compressors is disclosed in U.S. Pat. No. 4,729,228 (Suction Line Flow Stream Separator For Parallel Compressor Arrangements), the teachings and disclosure of which is incorporated in its entirety herein by reference thereto.
Additionally, oil distribution systems for multiple-compressor arrangements are disclosed in U.S. Patent Pub. No. 2014/0056725, published Feb. 27, 2014; U.S. Patent Pub. No. 2014/0037483, published Feb. 6, 2014; and U.S. Patent Pub. No. 2014/0037484, published Feb. 6, 2014, each of which is assigned to the assignee of the present application. The teachings and disclosures of these publications are incorporated in their entireties herein by reference thereto.
For example, when distributing oil from one compressor to another in a refrigeration system having multiple compressors, the amount of oil distributed is at least partly dependent on the oil available to be drawn into the opening of an oil-supplying compressor such that the oil can then be distributed to one or more downstream oil-receiving compressors in the refrigeration system. It is also dependent on the oil sump pressures in the compressors.
Embodiments of the invention provide an advancement over the state of the art with respect to oil distribution in multiple-compressor systems. These and other advantages of the invention, as well as additional inventive features, will be apparent from the description of the invention provided herein.